The study contributes to the knowledge of the semi-desert and desert communities of the southern Alashan Gobi (Ejina Qi area) and the montane slopes and foothills of the northern Qilian Shan, Beishan, and Ya Gan Mts. of northwestern China. It follows the traditional BRAUN-BLANQUET approach.
Stone and gravel deserts are the most common and most impressive feature of the landscape, typical of the more or less flat and extended alluvial plains, terraces and depressions. In addition, dunes and aeolian sands occur, dominated by psammophytic phytocoenoses. Outstanding and very prominent is
the Ruoshui river system, its inland delta and endorheic basins, which drains the whole area. As most parts of the area receive less than 60 mm rainfall per year, xerophytic semishrubs and dwarf-shrubs give a peculiar appearance to this desert. The zonal vegetation drastically changes from shrub
semi-deserts and montane dwarf-shrub communities ( Sympegma montane steppe) in the surrounding mountains, to a very open desert steppe, dominated by dwarf-shrubs, such as Artemisia tschernieviana, Ephedra przewalskii, Nitraria sphaerocarpa, Reaumuria soongorica, and Zygophyllum
xanthoxylon . Trees are a rarity and exclusively linked with the groundwater flow of the Ruoshui, where phreatophytes, such as Populus euphratica and Tamarix ramosissima, dominate the natural riparian woodland. Frequently intermixed are aeolian sands, dunes and salty depressions
(solonchak formation) with various psammophytes [e. g., Calligonum mongolicum, Haloxylon ammodendron ('black saxaul')] and halophytes (e. g., Aeluropus littoralis var. sinensis, Kalidium foliatum, Salicornia perennans ). They form the azonal vegetation of the whole area.
Grasslands ( Achnatherum splendens ) and marshes ( Phragmites reed) occur around flood plain depressions, stream sides and the endorheic basins, providing an important grazing resource for the local people and their life-stock. In total, five classes, six orders, six alliances,
seven associations, three subassociations and eight rankless communities are treated for the first time from this part of China. Six of the units are described as new (viz., Asterothamno centrali-asiatici-Gymnocarpetum przewalskii, Nitrario sphaerocarpae-Artemisietum tschernievianae, with the
subassociations typicum, lycietosum ruthenicae, and calligonetosum mongolicae, Salicornio perennantis-Aeluropetum sinensis, Halerpesto cymbalariae-Crypsietum aculeatae). They provide the basis for the comparison of the vegetation of the study area with the units described from the neighbouring
Mongolia, which remain the single syntaxonomic reference for this part of Central Asia.

Phytocoenologia (ISSN 0340-269X) is an international, peer-reviewed journal of plant community ecology. It is devoted to vegetation survey and classification at any organizational and spatial scale and without restriction to certain methodological approaches. The journal publishes original papers that develop new vegetation typologies as well as applied studies that use such typologies, for example, in vegetation mapping, ecosystem modelling, nature conservation, land use management or monitoring. Particularly encouraged are methodological studies that design and compare tools for vegetation classification and mapping, such as algorithms, databases and nomenclatural principles. Papers dealing with conceptual and theoretical bases of vegetation survey and classification are also welcome. While large-scale studies are preferred, regional studies will be considered when filling important knowledge gaps or presenting new methods.

Phytocoenologia was founded by Reinhold Tüxen in 1973 and is published in collaboration with the International Association for Vegetation Science (IAVS; www.iavs.org). The journal closely cooperates with various subgroups of IAVS and serves as publication outlet for their workshops as well as for selected sessions of the IAVS Symposia. It contains special sections on “Phytosociological Nomenclature” and “Ecoinformatics”. Guest-edited Special Features that fall within the scope of the journal are also published.